Self extinguishing candles and method of making same

ABSTRACT

A self-extinguishing candle and method of making the candle are described. The self-extinguishing candle comprises a candle body formed of a candle base material and a flame retardant. The flame retardant is capable of extinguishing the candle flame or, alternatively, of controlling the candle flame.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. patentapplication Ser. No. 09/874,669 filed on Jun. 5, 2001 which claimspriority to U.S. Provisional patent application, Serial No. 60/210,057,filed Jun. 7, 2000, the disclosures of which are incorporated byreference herein in their entirety.

FEDERALLY SPONSORED RESEARCH

[0002] Not applicable.

REFERENCE TO MICROFICHE APPENDIX

[0003] Not applicable.

FIELD OF THE INVENTION

[0004] The invention relates to self-extinguishing candles and methodsof making candles.

BACKGROUND OF THE INVENTION

[0005] Since their earliest use, candles have provided a convenient andgenerally reliable source of light for mankind. While candles havevaried substantially through the years, all generally comprise a solidfuel source (usually wax) within which a fiber wick is embedded. Intheir basic function, candles provide light once the fiber wick is litby producing sufficient heat to melt the wax fuel to a liquid form whichmay be carried within the wick and burned. As the candle flame burns,the heat produced creates a pool of melted wax in the region of thewick. This liquified or melted wax is then carried up to the flame bycapillary action within the wick. As the candle burns, and the wax fuelis consumed, the position of the flame moves downwardly upon the wickpermitting the candle to produce a substantially continuous light.

[0006] As long as the fuel is supplied through the wick via a capillaryaction to the flame, the flame continually bums down the wick. In manysituations, the candle is lit and left alone to bum until the candle ismanually extinguished or extinguishes itself. A typical candle willnormally extinguish itself upon the disintegration of the wick or theelimination of the fuel supply to the wick.

[0007] Many commercially sold wax candles, however, are often placed orformed in a glass or other fragile non-flammable container. Therefore,as the flame disintegrates the wick, the flame approaches the bottom ofthe glass candle holder, thereby causing the glass holder to experienceexcessive heating. In certain conditions, the excessive heating resultsin thermally induced cracking or breakage failures. Specifically, whenthe heat inside the glass container exceeds the heat stress limits ofthe glass container, the glass may crack or completely break. If a glasscandle holder breaks, flying glass pieces, fire hazards, and bums frompicking up hot pieces of glass and wax may result in various levels ofinjury and/or property damage.

[0008] Typical candles will often self-extinguish when approximately0.25 inches of wax residue is left in the bottom of the glass holder.However, allowing a candle to bum with only 0.25 inches of wax residuebetween the flame and bottom of the glass is often dangerous in that, asdiscussed above, the flame still provides excessive heat to the glasssurface. To further separate the flame from the glass surface and toprovide stability to the wick, the bottom end of the wick is typicallyinserted into a wick clip. An exemplary wick clip is often constructedof a thin metal or aluminum material which includes a wide base forsupporting a hollow cylindrical ferrule, whereby the cylindrical ferruleis typically located in the center of the base. The center of the baseoften includes an opening allowing fuel access from underneath the baseinto the hollow ferrule.

[0009] Other candles, such as pillar candles, are free-standing, neitherpoured nor placed into a holder. As the candle bums down, the flameapproaches the surface on which the candle is placed and may mar, charor bum the surface. If a free-standing candle is left unattended and isallowed to bum very low, the melted wax could flow out of candle andover the surface. Furthermore, as the flame approaches the bottom of thewick, a free-standing candle poses a safety hazard as the flame couldignite the surface on which the candle sits.

[0010] Alternatively, some candles, both free-standing and jar candles,are manufactured to include a wick holder formed from a round base witha cylindrical ferrule emanating from the center of the round base. Thecylindrical ferrule is hollow as to allow one end of the wick to bereciprocally received therein. The upper portion of the ferrule is “S”crimped, without piercing the ferrule, to reduce the flow of fuel upwardthrough the ferrule. The base of the wick holder includes a smallopening in the center of the base which is concentric with, and the samediameter as, the opening in the cylindrical ferrule. The bottom of thebase, on the opposite side of the cylindrical ferrule, is completelysealed off by a hot-melt adhesive, thereby preventing fuel fromtraveling up the hollow ferrule.

[0011] By reducing the flow of fuel within the wick holder, the wickholder restricts the supply of fuel to the candle wick when the flameburns the candle wick down to the top of the wick holder ferrule. Byrestricting the supply of fuel to the wick, the candle flame, uponburning down to the top of the wick holder, self-extinguishes beforeallowing the flame to approach the surface of the glass candle holder.

[0012] The aforementioned candles are based on restricting the flow ofliquid wax to the wick by a mechanical device. Therefore, the ability ofthe candles to self-extinguish depends upon the performance of therestricting device. If the restricting device fails to function, thecandle would not self-extinguish at the desired point. Therefore, thereis need for a candle that self-extinguishes at the desired point withimproved consistency.

[0013] It has also been observed that candles frequently burn with toolarge a flame and expend the candle too quickly. Although the wick canbe manually trimmed to decrease the flame size, this necessitatesextinguishing the candle and allowing the wick to cool. Furthermore,trimming the wick does not prevent the rapid consumption of the candle.There is a need, therefore, for a candle in which the rate of fuelconsumption, and therefore flame size, is controlled.

SUMMARY OF THE INVENTION

[0014] Embodiments of the invention meet the aforementioned need by oneor more of the following aspects. In one aspect, a self-extinguishingcandle is provided. The self-extinguishing candle includes a candle bodyformed of a candle base material, and a wick. All or part of the candlebody includes at least one flame retardant as an additive.

[0015] The flame retardant in accordance with the embodiments of theinvention may be a solid insoluble or partially soluble in the candlebase material. In some embodiments, the flame retardant may function byflowing into and partially or totally clogging the wick therebyrestricting or preventing the flow of the candle base material into andthrough the wick. As a consequence, the flame may be limited and/orcontrolled or extinguished.

[0016] Alternatively, the flame retardant in accordance with theembodiments of the invention may be a flame-extinguishing orflame-controlling, non-combustible, material which flows into andthrough the wick. In such embodiments, the flame retardant either limitsand/or extinguishes the flame. Such material may be a solid or a liquid.The clogging-form, flame-controlling, and the flame-extinguishing formof flame retardants are collectively referred to herein as a flameretardant.

[0017] In one embodiment, the self-extinguishing candle includes acandle body formed from a candle base material and having a bottomportion which further includes at least one flame retardant.

[0018] In another aspect, the self-extinguishing candle includes acandle body formed from a candle base material and at least one flameretardant wherein the flame retardant concentration increases from a lowconcentration at the top of the candle body, where the candle is lit, toa high concentration at the bottom of the candle body.

[0019] In another aspect, a method of making a self-extinguishing candleis provided. The method includes: (a) forming a candle body from acandle base material and at least one flame retardant wherein the flameretardant is evenly distributed throughout the candle body.

[0020] Additional aspects of the invention as well as objects andadvantages provided by embodiments of the invention are apparent withthe following description.

DESCRIPTION OF THE DRAWINGS

[0021] Not applicable.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0022] Embodiments of the invention provide a self-extinguishing candlewhich includes a candle body formed of a candle base material. In afirst embodiment, the candle body further includes a substantiallyuniformly distributed flame retardant additive. The flame retardant maybe present in amounts from about 0.01% to about 50% by weight; morepreferably, from about 0.05% to about 20% by weight; and mostpreferably, from about 0. 1% to about 10% by weight.

[0023] The terms “flame retardant additive” and “flame retardant” asused herein mean any compound, composition or material whichextinguishes and/or controls a flame. These terms includesolid-clogging, flame extinguishing and flame limiting forms.

[0024] In a second embodiment, the distribution of flame retardant isnon-uniform, with a greater concentration of the flame retardant in alower portion of the candle body. Most preferably, there exists agradient of increasing flame retardant weight percentage over the heightof the candle, having from about 0% to about 10% flame retardant at thetop of a candle nearest the lightable end of the candle to from about90% to about 0.01% flame retardant at the bottom of the candle.

[0025] In yet another embodiment, the flame retardant concentration isdiscontinuous, with no flame retardant present toward a lightable end ofthe candle body and a flame-extinguishing concentration of a flameretardant present toward the bottom of the candle body. The flameretardant may range from about 0.01% to about 90% by weight toward thebottom portion of the candle body.

[0026] In some embodiments, the flame retardant is of the type or insufficient concentration to completely extinguish the flame. In otherembodiments, the flame retardant is of the type or in a concentration soas to control the flame such that the flame does not burn excessively orstronger than desired. Particularly useful for controlling the flame arethe solid, insoluble clogging forms of flame retardants. Such cloggingflame retardants, including but not limited to hydrophobic silica,restrict the flow of the candle base material to and/or through thewick.

[0027] Typically, the self-extinguishing candle includes one or morewicks inside or on the outside of the candle, although it is not alwaysnecessary to have a wick inside the candle. The wick may extendcompletely or partially through the candle body. Wickless candles whichare self-extinguishing may also be made in accordance with embodimentsof the invention.

[0028] The candle body of the self-extinguishing candle in accordancewith embodiments of the invention includes a candle base material. Theterm “candle base material” refers to any material that can be used toform a candle. A suitable candle base material preferably is a solidwhich upon melting, provides a fuel source to a burning wick. A suitablecandle base material can be solid, semi-solid, or liquid. Although mostcandle base material is opaque or substantially opaque, a transparent,substantially transparent or translucent material can also be used toform the candle body. Consequently, the self-extinguishing candles inaccordance with embodiments of the invention can be transparent, opaque,or translucent.

[0029] A common form of candle base material is wax, which usuallyrefers to a substance that is a plastic to brittle solid at ambienttemperature and becomes a low viscosity liquid upon being subjected toelevated temperatures. Suitable waxes for forming the candle bodyinclude any known waxes, including but not limited to, paraffin wax,microcrystalline wax, beeswax, insect wax, animal wax, vegetable wax,mineral wax, synthetic wax, polyethylene wax, and mixtures thereof. Inaddition to wax, semi-solids (such as petrolatum), liquids, syntheticmaterials, synthetic polymers, mixtures of synthetic materials, mixturesof synthetic polymers and synthetic materials, and mixtures of syntheticpolymers with one or more organic compounds may be used as a candle basematerial or part of a candle base material. Other typically used candlefuel source components, such as hydrocarbon oil, stearic acid, Vybar®,etc., also may be included in the candle base material. The followingU.S. patents disclose a suitable candle base material that can be usedin embodiments of the invention: U.S. Pat. Nos. 6,063,144; 6,036,925;4,855,098; 4,449,987; 4,332,548; and U.S. Pat. No. 4,005,978. Thedisclosures of all of the above U.S. patents are incorporated byreference herein in their entirety. It is noted that a wax can be usedalone or with one or more additives or gelling agents to form the candlebase material, depending on the type of candles desired.

[0030] The self-extinguishing candle can also have a translucent,transparent or substantially transparent candle body. Any translucent,or transparent candle base material may be used in embodiments of theinvention. For example, the following U.S. patents disclose a suitabletransparent candle composition which may be used in embodiments of theinvention: U.S. Pat. No. 5,879,694; 5,843,194; 5,578,089; 5,508,334;5,132,355; 3,819,342; and U.S. Pat. No. 3,645,705. In addition, U.S.Pat. No. 6,111,055 discloses a transparent polyamide-based gel that canbe used to form a transparent candle. As the terms are used herein,polyamides may be considered either a synthetic material or a syntheticpolymer. The disclosures of all of the above U.S. patents areincorporated by reference herein in their entirety. In addition, U.S.Pat. No. 5,961,967 discloses a multiphase candle containing locallyenriched regions of deliverable active ingredients. Such a candle mayalso be used in embodiments of the invention. Therefore, the disclosureof this patent is incorporated by reference herein in its entirety.

[0031] In some embodiments, the candle body may be formed from a candlebase material which is capable of undergoing a phase transition fromopaque to transparent or vice versa. PCT Application WO 99/27042discloses such a candle base material which is suitable for use inembodiments of the invention. The disclosure of this PCT application isincorporated by reference herein in its entirety. Moreover, U.S. Pat.No. 6,471,731, entitled “Polymeric Candle Compositions and Candles MadeTherefrom,” filed on Oct. 29, 2002 and U.S. patent application Ser. No.09/590,863, filed on Jun. 9, 2000 in the name of David Elliott, III,Richard L. Johnson, Wei Song as the inventors, disclose another candlebase material which is capable of under going a phase transition fromopaque to transparent. The disclosures of these provisional and utilityapplications are incorporated by reference herein in its entirety.

[0032] The flame retardants disclosed in The Chemistry and Uses of FireRetardants by J. W. Lyons, Wiley-Interscience (1970), can be used inthis invention. Thus, the disclosure of this book is incorporated byreference herein in its entirety. It is noted that a suitable flameretardant can be an inorganic compound, an organometallic compound, anorganic compound, or a mixture thereof. The flame retardant can beliquid, solid, or semi-solid. Hydrophobic silica, titanium dioxide(TiO₂), talc,, clay, diatomaceous earth, and liquid silicone may be usedas a flame retardant. Additional suitable flame retardants include, butare not limited to, lead-containing compounds, arsenic-containingcompounds, phosphorus-containing compounds, sulfur-containing compounds,alumina trihydrate, aluminum oxide (Al₂O₃), magnesium hydroxide,magnesium carbonate, calcium carbonate, boric acid, antimony trioxide,tris-1,3-dibromopropyl phosphate, ammonium phosphate,bis(bromochloropropyl) bromochloropropyl phosphate, chlorinatedparaffin, polybrominated diphenyloxide, decarbromophenoxybenzene,tetrabromobisphenol A, hexabromocyclododecane, tetrabromophthalicanhydride, or mixtures thereof. Additional suitable flame retardants aredisclosed in the following U.S. Pat. Nos. 6,005,033; 5,886,072;5,766,568; 5,710,202; 5,583,172; 5,578,666; 5,532,302; 5,521,003;5,418,272; 5,344,855; 5,296,534; 5,027,416; 5,185,103; 5,151,225;5,130,349; 5,030,674; 5,025,042; 5,011,736; 4,945,018; 4,921,897;4,900,768; 4,885,318; 4,869,948; 4,808,647; 4,740,537; 4,671,896;4,520,152; 4,456,654; 4,362,658; 4,350,793; 4,343,854; 4,320,038;4,235,978; 4,194,068; 4,184,969; 4,154,775; 4,115,351; 4,094,850;4,078,016; 4,067,930; 3,956,567; 3,953,650; 3,950,456; and U.S. Pat. No.3,941,908. The disclosures of all of the above U.S. patents areincorporated by reference herein in their entirety. Moreover, suitableflame retardants include a phosphorus/nitrogen-containing oligomer orpolymer as disclosed in U.S. Pat. No. 5,409,976, aphosphorus/nitrogen-containing compound as disclosed in U.S. Pat. No.5,158,999, a halogenated aliphatic bisimide as disclosed in U.S. Pat.No. 4,430,467, and thermally stable cyclic phosphonate esters asdisclosed in U.S. Pat. No. 4,842,609, and halogenated imide-containingpolyols as disclosed in U.S. Pat. No. 4,401,778. The disclosures of allof the preceding U.S. patents are incorporated by reference herein intheir entirety.

[0033] In some embodiments of phase-changing candles, paraffin wax withat least 20 carbon atoms per molecule (hereinafter “C₂₀₊ paraffin wax”)is used. C₂₀₊ paraffin wax refers to a wax composed of mainly paraffinswith 20 or more carbon atoms per molecule. In other words, the preferredC₂₀₊ paraffin wax is substantially free of paraffins with less than 20carbon atoms per molecule. Nevertheless, a small amount of paraffinswith less than 20 carbon atoms per molecule may be present in the C₂₀₊paraffin wax. Preferably, the melting point of the C₂₀₊ paraffin waxshould fall in the range of about 100° F. to about 200° F. (i.e., about37° C. to about 93° C.), more preferably in the range of about 100° F.to about 170° F., and most preferably in the range of about 110° F. toabout 165° F.

[0034] Paraffin wax is considered as a petroleum wax. It typically ismacrocrystalline and brittle. Paraffin wax usually is composed of about40 to about 90 weight percent of normal alkanes, with the remainderisoalkanes and cycloalkanes. Preferably, the paraffin wax does notinclude a substantial amount of hydrocarbons with less than 20 carbonatoms per molecule. Typical properties of paraffin wax are listed inTable I as follows. Examples of suitable paraffin waxes can be obtainedfrom Bareco under the trade names of Bareco Paraffin 120/125, Bareco FR5914, and Bareco FR 5315. TABLE I Typical Properties of Paraffin WaxFLASH POINT, CLOSED CUP. ° C. 204* VISCOSITY AT 98.9° C., MM²/S 4.2-7.4MELTING RANGE, ° C. 46-68 REFRACTIVE INDEX AT 98.9° C. 1.430-1.433NUMBER AVERAGE MOLECULAR WEIGHT 350-420 CARBON ATOMS PER MOLECULE 20-36DUCTILITY/CRYSTALLINITY OF SOLID WAX friable to crystalline

[0035] In some embodiments, wax alone or a mixture of waxes is used toform the candle body. In other embodiments, a polymer or a polymericmaterial is used alone or with a wax to form the candle base material.In still other embodiments, a wax is mixed with one or more additives tothe form the candle base material. The term “polymer” used hereinincludes both homopolymer and copolymer. A homopolymer is a polymerobtained by polymerizing one type of monomer, whereas a copolymer is apolymer obtained by polymerizing two or more types of monomers. “Blockcopolymer” refers to a copolymer in which like monomer units occur inrelatively long, alternate sequences on a chain.

[0036] Some polymers used in the candle base material often function asgelling agents. Any polymer which is capable of forming a threedimensional network or a gel through physical or chemical crosslinkingmay be used in embodiments of the invention. Suitable polymers include,but are not limited to, a copolymer with at least two blocks, i.e., adiblock copolymer, a triblock copolymer, a radial block copolymer, astar polymer, a multi-block copolymer, and mixtures thereof. Otherembodiments, the polymer includes at least one triblock copolymer,radial block copolymer, star polymer, or multi-block copolymer. Thecopolymer includes at least one rigid block and one elastomeric (orrubber-like) block. The rigid blocks of the copolymer form rigid domainsthrough which physical crosslinking may occur. The physical crosslinkingvia these rigid domains yields a continuous three dimensional network.In the presence of heat and shear or solvent, the rigid domains softenand permit flow. After cooling or solvent evaporation, the rigid domainsreform and harden, locking the elastomeric network in place. U.S. Pat.No. 5,221,534, U.S. Pat. No. 5,879,694 and U.S. Pat. No. 5,578,089disclose examples of such block copolymers, and the disclosures of thepatents are incorporated by reference in their entirety herein.

[0037] A diblock copolymer includes two blocks within its chains: arigid block and an elastomeric block. The rigid block typically may becomposed of polystyrene, polyethylene, polyvinylchloride, phenolics, andthe like; the elastomeric block may be composed of ethylene/butadienecopolymers, polyisoprene, polybutadiene, ethylene/propylene copolymers,ethylene-propylene/diene copolymers, and the like. As such, suitablediblock copolymers include, but are not limited to,styrene-ethylene/propylene copolymers, styrene-ethylene/butadienecopolymers, styrene-isoprene copolymers, styrene-butadiene copolymers.In some embodiments, a diblock copolymer is used along with one or moretriblock copolymers, star polymers, radial copolymers, and multi-blockcopolymers.

[0038] A triblock copolymer includes two rigid blocks at either end anda middle block which is elastomeric within its chains. This is apreferred triblock copolymer structure, although a triblock copolymerwith two elastomeric end blocks and a rigid middle block also can beused. Suitable triblock copolymers include, but are not limited to,styrene-ethylene/propylene-styrene copolymers,styrene-ethylene/butadiene-styrene copolymers, styrene-isoprene-styrenecopolymers, and styrene-butadiene-styrene copolymers. Multi-blockcopolymers are similar to diblock copolymers or triblock copolymers,except that the multiple block copolymers include additional elastomericblocks and/or rigid blocks.

[0039] In addition to the linear chain structure, branched homopolymersor copolymers, such as a radial polymer and a star polymer, also may beused. It should be noted that one or more functional groups may begrafted onto the chain of any of the aforementioned polymers. In otherwords, any of the above polymers may be modified by grafting. Suitablefunctional groups for grafting depend on the desired properties. Forexample, one or more ester groups, silane groups, silicon-containinggroups, maleic anhydride groups, acrylamide groups, and acid groups maybe grafted. In addition to grafting, the above polymers may behydrogenated to reduce unsaturation before they are used.

[0040] It is noted that additional suitable block copolymers mayinclude, but are not limited to, polystyrene/polyester,polyether/polyamide, polyether/polyester, polyester/polyamide,polyether/polyurethane, polyester/polyurethane, poly(ethyleneoxide)/poly(propylene oxide), nylon/rubber, andpolysiloxane/polycarbonate.

[0041] Generally, the weight average molecular weight of a suitablepolymer is in the range from about 10,000 to about 1,000,000, preferablyfrom about 70,000 to about 400,000. The rigid block content may rangefrom about 5% to about 80%, preferably from about 20% to about 40% byweight.

[0042] Numerous commercially available block copolymers may be used inembodiments of the invention. For example, various grades of copolymerssold under the trade name of Kraton® from Shell Chemical Company can beused. In addition, copolymers sold under the trade name of Vector®available from Dexco and Septon® from Kuraray also may be used. Calpreneand Solprene products listed in Table II are available from MomentumTechnologies, Inc. Table II lists some commercially available blockcopolymers which may be used in embodiments of the invention. TABLE IIBlock Polystyrene Copolymer Type Content(%) Comment Kraton ® G 1702 SEP28 Hydrogenated diblock Kraton ® G 1701 SEP 37 Hydrogenated diblockKraton ® G 1780 SEP 7 Star polymer Kraton ® G 1650 SEBS 30 Hydrogenatedtriblock Kraton ® G 1652 SEBS 30 Hydrogenated triblock Kraton ® D 1101SBS + SB 31 Triblock and diblock mixture (85:15) Kraton ® D 1102 SBS +SB 28 Triblock + diblock (85:15) Kraton ® D 1133 SBS + SB 35 Triblock +diblock (66:34) Kraton ® FG 1901 SEBS 30 Triblock (hydrogenated andfunctionally grafted with 1.7% of maleic anhydride. Septon ® 1001 SEP 35Hydrogenated diblock Vector ® 6030 SB 30 Unsaturated diblock Vector ®8550 SBS 29 Unsaturated triblock Vector ® 2518P SBS 31 Unsaturatedtriblock Calprene ® H6120P SEBS 30 Hydrogenated triblock Solprene ® 1430SB 40 Unsaturated diblock

[0043] It should be recognized that block copolymers are not the onlypolymers that can be used in embodiments of the invention. Other typesof polymers also may be used. Homopolymers which are capable ofeffecting strong molecular interaction between polymeric chains can beused. One such example is butyl rubber, which can thicken oil due to itscompatibility with oil and high molecular weight. Specifically, apolybutadiene polymer sold under the trademark of Solprene® S200, whichis available from Momentum Technologies, Inc., can be used. Otherhomopolymers capable of forming hydrogen bonding may include polyamide,polyester, etc. Other suitable polymers include ester terminatedpolyamide (ETPA), amide terminated polyamide (ATPA), other polyamidesand polyamide derivatives.

[0044] In those embodiments in which a polymer is present in a candlebase material, the polymer content may range from about 0.01 wt. % toabout 80 wt. %, although other composition ranges are acceptable. Insuch embodiments, a polymer is present in the candle base material fromabout 1 wt. % to about 65 wt. %. In embodiments where both a diblockcopolymer and a triblock copolymer are used, the triblock copolymer mayrange from about 0.01 wt. % to about 30 wt. %, and the diblock copolymerfrom about 0.01 wt. % to about 20 wt. %.

[0045] In some embodiments of formulating a candle base material, a waxand a polymer may be present in any amount. In some embodiments, acandle base material may be made from the following components: aparaffin wax or a mixture of waxes with at least 20 carbon atoms permolecule in an amount of about 2 to about 96% by weight, a blockcopolymer in an amount of about 0.01 to about 35% by weight, and ahydrocarbon oil in an amount of 0 to about 96% by weight. Additionaladditives and objects may be included during the manufacturing ofcandles.

[0046] Candle base materials and candle bodies in accordance with someembodiments of the invention may be prepared by blending a hydrocarbonoil and a wax with one or more triblock, radial block, and/ormulti-block copolymers, star polymers, or mixtures thereof, in desiredamounts. A diblock copolymer may also be optionally included. Ingeneral, the higher the polymer content, the stiffer the gel. Acceptablecompositions including a hydrocarbon oil, a wax and polymers aredisclosed in U.S. Pat. No. 6,340,467, and the disclosure of such patentis incorporated by reference in its entirety herein.

[0047] In some embodiments, a hydrocarbon oil and a suitable wax arefirst heated to a temperature in the range of about 50° C. to about 150°C., at which point a polymer is added under agitation to the desiredweight percent as set forth herein. After sufficient time for thecopolymer to dissolve in the mixture, the composition is poured into amold or a jar containing a wick. Alternatively, a wick may be addedthereafter, and the composition is allowed to cool to a stiff gel.

[0048] In some embodiments of the invention, the candle is formed bycooling the candle base material with flame retardant additive in a moldor jar. A mold is used to impart external features, for example, apillar candle, if desired. Conventional jars, clear, colored orotherwise decorative, such as sculpted, etched, cut glass, etc., may beemployed for holding the candle. More preferably, clear glass jars areused for a jar candle.

[0049] Candle base materials and candle bodies also may be formed byblending a suitable polymer (or a polymer blend) and a hydrocarbon oiland heating the mixture to a temperature in the range of from about 50°C. to about 150° C. to dissolve the polymer (or the polymer blend) inthe oil. A wax is then added under agitation. The wax is mixed with thehydrocarbon oil and the copolymer. Mixing may be carried out in anyconventional manner. Upon cooling, a stiff (and sometimes opaque) gelforms.

[0050] In addition to a wax and a polymeric material, a hydrocarbon oilmay be used in forming a candle base material. It is noted that ahydrocarbon oil may used with or without a polymeric material informulating a candle base material. Hydrocarbon oil refers to any oilthat is primarily composed of one or more compounds with hydrocarbonmoieties. Suitable hydrocarbon oils include, but are not limited to,vegetable oil, animal oil, insect oil, mineral oil, esters, or otheroil-soluble liquids. It also includes refined, aromatic-free paraffinicand naphthenic oils, solvents, synthetic liquids, hydrogenated orunhydrogenated oligomers of polybutene, polypropylene, polydecene, andpolyterpene. Other polyolefins also are suitable.

[0051] A preferred mineral oil is white oil which is colorless andtransparent and generally is recognized as safe for contact with humanskin. Another preferred hydrocarbon oil is poly-α-olefins (“PAOs”). Theterm “poly-α-olefin” refers to a class of saturated olefin oligomers. Atypical poly-α-olefin includes various amounts of dimers, trimers,tetramers, pentamers, hexamers of an α-olefin. A preferred PAO isoligomers of 1-decene, although it may be oligomers of any otherα-olefins. Another preferred oil is hydrogenated polyisobutene.

[0052] In some embodiments of the invention, the self-extinguishingcandle is formed by pressing a particulate candle base material with aflame retardant in a mold. Such pressure molding may occur at ambient orelevated temperatures, with the pressure causing the candle basematerial particulates to meld into a solid unit.

[0053] The self-extinguishing candles in some embodiments employ one ormore wicks, typically of porous material which may be either waxed orunwaxed and of the thickness and type appropriate for the particularcandle design. Any wick may be used. The wick or wicks may include adecorative feature, for example, striping, coloring, impregnation orcoated with material for special effects, such as to provide a coloredflame, sparkles, etc., if so desired.

[0054] The self-extinguishing candles in accordance with embodiments ofthe invention also may contain one or more additives such asstabilizers, U.V. inhibitors, antioxidants, colorants, fragrances, flameretardants, and the like to an extent not adversely affecting ordecreasing the desired properties of the candle. Stabilizers and othersuitable additives include, but are not limited to, performanceenhancing additives, materials which improve the candle's burnproperties, materials which improve the candle's appearance, and thelike to an extent not adversely affecting or decreasing the desiredproperties of the candle. With respect to antioxidants, specificreference is made to 2,6-di-tert-butyl-4-methylphenol known as “BHT,”which is generally employed at about 0.0 to about 1 weight percent.Other antioxidants also may be used. These additives can be placed inthe candle body, the flame resistant block, or both.

[0055] Colorants may be added to the candles. The candles may bemulticolored or have colored layers. The latter is achieved by formingone colored layer, allowing the layer to cool, and overlaying with asecond colored layer, and so on. Other designs can be employed, such assingle or multi-color swirls. Such swirls can be achieved by adding thecolor to the candle base material at a time during cooling of thecomposition but prior to complete solidification, and gently stirringthe composition. Still other design variations are apparent to thoseskilled in the art.

[0056] In addition to colorants, ornamental features may be embeddedwithin the candle body, the flame resistant block, or both. Suchfeatures may be either insoluble or soluble in the respectivecomposition of the candle, as desired. Use of such ornamental featuresallows a possibility not heretofore available in decorative features, asvirtually any decorative object can be incorporated within the candlebody, provided generally that such decorative feature does not adverselyaffect the burning capacity of the candle in an undesired way.

[0057] Notwithstanding the above, decorative and other functionalfeatures that interfere with the burning of the candle may beincorporated, if so desired. For example, in suitable candle designs,decorative features located near the periphery of the candle and not incommunication with the wick or flame will not adversely affect theoperation of the candle and may thus be of any sort desired. Such adecorative feature may be placed in the candle, for example, by additionto the candle base material after sufficient cooling of the melt butbefore complete solidification.

[0058] Exemplary decorative features include glitter, sparkles, ribbons,air bubbles of various size, and other soluble, partially soluble andinsoluble embeds. A pearlizing agent may be used in the candle. Otherdecorative additives, such as those that cause special effects, e.g.,sparkling, flame coloring, etc., or mixtures thereof, also may be addedto the candle base material of the candle in effective amounts and asdesired. In addition, fluorescent and phosphorescent pigments or dyesmay be added to enhance the appearance of the candle. U.S. Pat. No.6,433,068, entitled “Hydrocarbon Gels as Suspending and DispersingAgents and Products,” discloses a suspension system which can be used inembodiments of the invention. The disclosure of this patent isincorporated by reference in its entirety herein.

[0059] Fragrances, for example, cinnamon, spice, bayberry, pine, essenceoils, etc., also may be used in a manner similar to the way wax candlesemploy pleasing aromatic additives. Any fragrances soluble in orotherwise compatible with the candle composition may be used in makingthe candles. These fragrances can be employed by inclusion into theheated candle base material. Alternatively, if the fragrance isparticularly volatile, it is preferably added to the cooling compositionprior to complete solidification. Fragrances are generally employed atup to about 20% by weight of the total candle base material. However, itis recognized by those skilled in the art that fragrant additives can beused up to their characteristic solubility level in the composition ofthe candle.

[0060] The self-extinguishing candles in accordance with embodiments ofthe invention may further contain a functional additive, such as aninsect repellant, for use in the same capacity as conventional candlescontaining such an additive. The flame retardant may be present inamounts from about 0.01% to about 50% by weight; more preferably fromabout 0.1% to about 35% by weight; and most preferably from about 0.5%to about 10% by weight. For example, U.S. Pat. No. 5,387,418 disclosesone such insect repellant compound that may be employed in the candles.The disclosure of the patent is incorporated by reference herein in itsentirety. Citronella oil is another example of an insect repellant thatmay be used in embodiments of the invention. These additives are used inthe conventional amounts as known in the art.

[0061] The following examples are presented to illustrate the inventionbut are not to be considered as limiting the invention. The followinginclude examples of each of the three types of self-extinguishingcandles: (1) those in which the flame retardant is evenly distributedthroughout the candle; (2) those in which the flame retardant isdistributed as a gradient with a higher distribution at the bottom ofthe candle; and (3) those in which the flame retardant is present onlyin a lower portion of the candle. The Kraton® polymers used in theseexamples were obtained from Shell Chemical Company. FR 5914 and FR 5315,referred to in the examples below, are paraffin waxes sold under theBareco trade name. Micro 195, a microcrystalline wax, was obtained fromBareco, Vybar 103, Vybar 260, and Vybar 343 were obtained from BakerPetrolite. Calprene H 6120P was obtained from Momentum Technologies,Inc.

EXAMPLE 1

[0062] A candle base material of 69.9 grams FR 5914, 10 grams FR 5315,10 grams white petrolatum, and 0.10 grams Kraton G1650. 0.1 grams ofAerosil R 972, a fumed silica composition, was added to the candle basematerial and mixed. A candle was prepared with an appropriately sizedwick. The resulting candle was lit and the flame self-extinguished after6 minutes and 30 seconds.

EXAMPLE 2

[0063] A candle base material containing 70.5 grams Bareco FR 5315, 4grams Micro 195, 3 grams Vybar 260, 10 grams Yellow Beeswax, 10 gramsSoy Wax, and 1 grams Calprene H 6120P was prepared. 1.5 grams talc wasadded to the candle base material and permitted to partially settle suchthat there was a larger concentration of talc at the bottom of theresulting candle than at the top of the candle. The candle was lit andself-extinguished after 30 minutes of burning.

EXAMPLE 3

[0064] A candle base material containing 66.9 grams Bareco FR 5914, 5grams Bareco FR 5315, 15 grams white petrolatum, 3 grams Micro 195, 3grams Stearic Acid, 4 grams Yellow Beeswax and 0.1 grams Ajinomoto GP-1,was prepared. 3 grams bentonite clay was added to a candle beforehardening of the base material so as to obtain a greater concentrationof the clay at the bottom of the candle than at the top of the candle.Ajinomoto GP-1 is a dibutyl lauroyl glutamide compound. The candle waslit and self-extinguished after 8 minutes and 20 seconds.

EXAMPLE 4

[0065] A candle base material containing 56.2 grams Bareco FR 5914, 36.7grams Bareco FR 5315 1.5 grams white petrolatum, 0.7 grams Stearic Acid,3.8 grams yellow beeswax, and 0.1 grams Kraton G1701 was prepared. 1grams of fumed silica was added to the base material. A candle was thenprepared using an appropriate wick and the resulting candle hadsubstantially constant concentration of the fumed silica throughout. Thecandle was lit and it burned with a small flame. The candleself-extinguished after about 2 hours.

EXAMPLE 5

[0066] A candle base material containing 85.0 g Bareco FR 5914, 5.0 gBareco FR 5315, 3.0 g Bareco Micro 195, 1.0 g Stearic Acid, and 1.0 gYellow Beeswax was heated to 90° C. with stirring. To this mixture wasadded 2.0 g Kraton G1650 and 2.0 g Kraton G1702. The blend was stirreduntil the polymers were dissolved and the mixture was uniform andhomogeneous. Aerosil R972 (1.0 g) was added to the candle base material.A candle was prepared from this material, with the Aerosil beinguniformly distributed throughout the candle. When the candle was lit, itself-extinguished after 1 minute and 30 seconds.

EXAMPLE 6

[0067] A candle base material containing 87.90 g Bareco FR 5914, 0.10 gVybar 103, 3.00 g Stearic Acid, 1.00 g Kraton G1654, 1.00 g Kraton GRP6917, 2.00 g Kraton D1102, and 5.00 g Dow Corning 200 Silicone Fluid(350 cSt) was prepared and made into a candle. The silicone fluid wasevenly dispersed throughout the candle. When lit, the candle burnedsteadily, with a small, controlled flame.

EXAMPLE 7

[0068] A candle base material containing 76.0 g Bareco FR 5315, 5.0 gWhite Petrolatum, 10.0 g Bareco Micro 195, 8.0 g Kraton G1652, and 1.0 gStearyl Methicone was prepared. This was made into a candle with theStearyl Methicone being distributed evenly throughout the candle. Whenlit, the candle had a steady burn, with a very small flame.

EXAMPLE 8

[0069] A candle base material was prepared from 87.0 g Bareco FR 5914,10.0 g White Petrolatum, and 2.0 g Bareco Micro 195. To the bottomportion of this candle base material was added enough Aerosil R972 togive a concentration of 1 wt %, while the top portion of the candlecontained no Aerosil R972. When this candle was lit, it burned as anormal candle until the flame reached the region of the candle whichcontained the Aerosil. At this point, the candle self-extinguished andcould not be re-lit.

EXAMPLE 9

[0070] A candle base material containing 85.0 g Bareco FR 5914, 3.0 gBareco Micro 195, 1.0 g Stearic Acid, and 10.0 g Yellow Beeswax washeated until melted. To this was added 1.0 g Aerosil R972. A candle wasprepared from this base, which self-extinguished after burning for 2minutes.

EXAMPLE 10

[0071] A candle base material containing 68.50 g Bareco FR 5914, 19.00 gBareco FR 5315, 2.00 g White Petrolatum, 3.00 g Stearic Acid, and 5.00 gYellow Beeswax was heated until melted. To this was added 2.50 g AerosilR972. A candle was prepared from this base, which self-extinguishedafter burning for 3 minutes.

EXAMPLE 11

[0072] A candle base material containing 81.20 g Bareco FR 5315, 5.00 gWhite Petrolatum, 10.00 g Bareco Micro 195, and 3.00 g Kraton G1652 wasmixed with heating until homogeneous. To this was added 0.80 g AluminumOxide with stirring. This was made into a candle, with uniformdispersion of the aluminum oxide throughout the candle. When lit, thecandle burned very slowly to completion, with a very small flame.

EXAMPLE 12

[0073] A candle base material containing 86.70 g Bareco FR 5914, 0.30 gVybar 103, 3.00 g Stearic Acid, and 5.00 g Kraton G1702 was heated untilall the solids had melted or dissolved. To this was added 5.00 gTitanium Dioxide. A candle, with even dispersion of the titaniumdioxide, was prepared from this base. The candle was lit, and itself-extinguished after 5 minutes.

EXAMPLE 13

[0074] A candle base material containing 90.0 g Soy Wax, 6.0 g Bareco FR5315, and 3.0 g Vybar 260, was prepared. To this was added 1.0 g AerosilR972 with mixing. This base, with evenly-dispersed Aerosil, was madeinto a candle, which self-extinguished 20 seconds after being lighted.

EXAMPLE 14

[0075] A candle base material containing 85.40 g Bareco FR 5315, 2.50 gBareco Micro 195, 0.10 g Vybar 260, 6.00 g Yellow Beeswax, and 4.00 gKraton G1652 was heated with stirring until the mixture was uniform andhomogeneous. To this was added 2.00 g Bentonite Clay. A candle, withuniform dispersion of the bentonite clay throughout, was prepared fromthis base. The candle self-extinguished after burning for 15 minutes.

EXAMPLE 15

[0076] A candle base material containing 51.00 g Bareco FR 5914, 4.00 gBareco FR 5315, 15.00 g White Petrolatum, 3.00 g Bareco Micro 195, 3.00g Stearic Acid, 4.00 g Yellow Beeswax, 5.00 g Soy Wax, and 5.00 g KratonG1650 was heated with stirring until the mixture was smooth andhomogeneous. To this was added 10.00 g Talc, with stirring. A candle,with even dispersion of the talc, was prepared from this base. Thecandle was lit, and it self-extinguished after 1 minute and 10 seconds.

[0077] A demonstrated above, embodiments of the invention provide aself-extinguishing candle which may have one or more of the followingadvantages. First, because the candle extinguishes automatically afterthe candle base material is consumed by the candle flame, there islittle or no need for a candle extinguishing device, such as a candlesnuffer. The self-extinguishing feature of the candle should providesome peace of mind to consumers. Also due to its self-extinguishingfeature, fire safety should improve. Finally, due to its designsimplicity, it is relatively cost effective to manufacture theself-extinguishing candle. Other advantages are apparent to a person ofordinary skill in the art.

[0078] While the invention has been described with respect to a numberof embodiments, modifications and variations exist. For example, insteadof creating a single flame resistant portion in a candle, multiple flameresistant regions may be used. The flame resistant region need not beopaque; it can also be transparent or translucent. Colorants may also beadded to the flame resistant region to enhance aesthetic appeal. Theappended claims intend to cover all such variations and modifications asfall within the scope of the invention.

What is claimed is:
 1. A candle comprising: a candle body comprising: acandle base material; a flame retardant; and a wick, wherein the flameretardant is substantially uniformly distributed throughout the candlebody.
 2. The candle of claim 1 wherein the flame retardant is selectedfrom the group consisting of hydrophobic silica, liquid silicone,titanium dioxide, clay, diatomaceous earth, and mixtures thereof.
 3. Thecandle of claim 1 wherein the flame retardant is selected from the groupconsisting of aluminum oxide, alumina trihydrate, magnesium hydroxide,magnesium carbonate, calcium carbonate, boric acid, antimony trioxide,and mixtures thereof.
 4. The candle of claim 1 wherein the flameretardant is selected from the group consisting oftris-(1,3-dibromopropyl) phosphate, ammonium phosphate,bis(bromochloropropyl) bromochloropropyl phosphate, chlorinatedparaffin, polybrominated diphenyloxide, decarbromophenoxybenzene,tetrabromobisphenol A, hexabromocyclododecane, tetrabromophthalicanhydride, and mixtures thereof.
 5. The candle of claim 1 wherein thecandle body contains from about 0.01% to 50% by weight flame retardant.6. The candle of claim 1 wherein the candle body contains from about0.05% to about 20% by weight flame retardant.
 7. The candle of claim 1wherein the candle body contains from about 0.1% to about 10% by weightflame retardant
 8. The candle of claim 1 wherein the candle basematerial includes a wax.
 9. The candle of claim 8 wherein the wax isselected from the group consisting of paraffin wax, microcrystallinewax, beeswax, animal wax, insect wax, vegetable wax, mineral wax,synthetic wax, polyethylene wax, and mixtures thereof.
 10. The candle ofclaim 1 wherein the candle base material includes a wax and a gellingagent.
 11. The candle of claim 8 wherein the gelling agent is a di-blockcopolymer, tri-block copolymer, radial copolymer, star polymer,multi-block copolymer, a polyamide, an ester terminated polyamide, anamide terminated polyamide, polyamide derivatives, polybutadiene, or amixture thereof.
 12. The candle of claim 1 wherein the candle basematerial includes a hydrocarbon oil.
 13. The candle of claim 1 whereinthe candle body further comprises one or more soluble, partially solubleor insoluble embeds, or a mixture thereof.
 14. The candle of claim 1wherein the flame retardant is present in at least a flame-extinguishingconcentration.
 15. The candle of claim 1 wherein the flame retardant ispresent in a flame-controlling amount.
 16. The candle of claim 2 whereinthe flame retardant restricts the flow of candle base material throughthe wick.
 17. A candle comprising: a candle body having a lightable endand bottom end and comprising: a candle base material; a flameretardant; and a wick, wherein the flame retardant is distributed in thecandle body in a gradient with a flame-extinguishing concentration offlame retardant at the bottom end and a lower concentration of flameretardant at the lightable end.
 18. The candle of claim 17 wherein theflame retardant is selected from the group consisting of hydrophobicsilica, liquid silicone, titanium dioxide, clay, diatomaceous earth, andmixtures thereof.
 19. The candle of claim 17 wherein the flame retardantis selected from the group consisting of aluminum oxide, aluminatrihydrate, magnesium hydroxide, magnesium carbonate, calcium carbonate,boric acid, antimony trioxide, and mixtures thereof.
 20. The candle ofclaim 17 wherein the flame retardant is selected from the groupconsisting of tris-(1,3-dibromopropyl) phosphate, ammonium phosphate,bis(bromochloropropyl) bromochloropropyl phosphate, chlorinatedparaffin, polybrominated diphenyloxide, decarbromophenoxybenzene,tetrabromobisphenol A, hexabromocyclododecane, tetrabromophthalicanhydride, and mixtures thereof.
 21. The candle of claim 17 wherein thecandle base material includes a wax.
 22. The candle of claim 21 whereinthe wax is selected from the group consisting of paraffin wax,microcrystalline wax, beeswax, animal wax, insect wax, vegetable wax,mineral wax, synthetic wax, polyethylene wax, and mixtures thereof. 23.The candle of claim 17 wherein the candle base material includes a waxand a gelling agent.
 24. The candle of claim 23 wherein the gellingagent is a di-block copolymer, tri-block copolymer, radial copolymer,star polymer, multi-block copolymer, a polyamide, an ester terminatedpolyamide, an amide terminated polyamide, polyamide derivatives,polybutadiene, or a mixture thereof.
 25. The candle of claim 17 whereinthe candle base material includes a hydrocarbon oil.
 26. The candle ofclaim 17 wherein the candle body further comprises one or more soluble,partially soluble or insoluble embeds, or a mixture thereof.
 27. Acandle comprising: a candle body having a top lightable portion and abottom portion wherein the top portion comprises a candle base materialand the bottom portion comprises a candle base material and a flameretardant, and a wick extending from the top lightable portion throughat least part of the candle body.
 28. The candle of claim 27 wherein theflame retardant is selected from the group consisting of hydrophobicsilica, liquid silicone, titanium dioxide, clay, diatomaceous earth, andmixtures thereof.
 29. The candle of claim 27 wherein the flame retardantis selected from the group consisting of aluminum oxide, aluminatrihydrate, magnesium hydroxide, magnesium carbonate, calcium carbonate,boric acid, antimony trioxide, and mixtures thereof.
 30. The candle ofclaim 27 wherein the flame retardant is selected from the groupconsisting of tris-(1,3-dibromopropyl) phosphate, ammonium phosphate,bis(bromochloropropyl) bromochloropropyl phosphate, chlorinatedparaffin, polybrominated diphenyloxide, decarbromophenoxybenzene,tetrabromobisphenol A, hexabromocyclododecane, tetrabromophthalicanhydride, and mixtures thereof.
 31. The candle of claim 27 wherein thebottom portion of the candle body contains from about 0.01% to 50% byweight flame retardant.
 32. The candle of claim 27 wherein the bottomportion of the candle body contains from about 0.05% to about 20% byweight flame retardant.
 33. The candle of claim 27 wherein the bottomportion of the candle body contains from about 0.1% to about 10% byweight flame retardant
 34. The candle of claim 27 wherein the candlebase material includes a wax.
 35. The candle of claim 34 wherein the waxis selected from the group consisting of paraffin wax, microcrystallinewax, beeswax, animal wax, insect wax, vegetable wax, mineral wax,synthetic wax, polyethylene wax, and mixtures thereof.
 36. The candle ofclaim 27 wherein the candle base material includes a wax and a gellingagent.
 37. The candle of claim 36 wherein the gelling agent is adi-block copolymer, tri-block copolymer, radial copolymer, star polymer,multi-block copolymer, a polyamide, an ester terminated polyamide, anamide terminated polyamide, polyamide derivatives, polybutadiene, or amixture thereof.
 38. The candle of claim 27 wherein the candle basematerial includes a hydrocarbon oil.
 39. The candle of claim 27 whereinthe candle body further comprises one or more soluble, partially solubleor insoluble embeds, or a mixture thereof.
 40. The candle of claim 28wherein the flame retardant restricts the flow of candle base materialthrough the wick.